A new technique has been described for measuring the adhesive strength of a gingival cell line to an agar substratum by the modification of the original "blister" test for adhesives. A cell monolayer was developed on a Petri dish with a hole in the center of the growing surface, overlayed with agar, and the system pressurized to debond the cells from the agar surface. Pressure changes were measured by a capacitance pressure transducer the output of which was measured by a strip-chart recorder. The modulus (E) of the agar overlay was determined and used in the calculation of the adhesive-bond strength (gamma a). The gamma a yield for the gingival cell line (cell-agar debond) was 48.8 ergs per cm2, and for the control (no cells) (agar-polystyrene debond) was 30.0 ergs per cm2. This technique is being utilized to tabulate the adhesion of various cells to an agar overlay medium. In addition, selected cells are being studied for their binding ability to any inanimate substratum. This latter technique for cell-rigid substratum adhesion measurements will allow the testing of any non toxic inanimate material.